Coolant-containing composition, use for same, refrigerator having same, and method for operating refrigerator

ABSTRACT

An object is to provide a mixed refrigerant having three types of performance, i.e., a refrigerating capacity and a coefficient of performance that are equivalent to those of R410A, and a sufficiently low GWP. Provided as a means for achieving the object is a composition comprising a refrigerant, the refrigerant comprising trans-1,2-difluoroethylene (HFO-1132(E)), trifluoroethylene (HFO-1123), and 2,3,3,3-tetrafluoro-1-propene (R1234yf).

TECHNICAL FIELD

The present disclosure relates to a composition comprising a refrigerant, use of the composition, a refrigerating machine having the composition, and a method for operating the refrigerating machine.

BACKGROUND ART

R410A is currently used as an air conditioning refrigerant for home air conditioners etc. R410A is a two-component mixed refrigerant of difluoromethane (CH₂F₂: HFC-32 or R32) and pentafluoroethane (C₂HF₅: HFC-125 or R125), and is a pseudo-azeotropic composition.

However, the global warming potential (GWP) of R410A is 2088. Due to growing concerns about global warming, R32, which has a GWP of 675, has been increasingly used.

For this reason, various low-GWP mixed refrigerants that can replace R410A have been proposed (PTL 1).

CITATION LIST Patent Literature PTL 1: WO2015/141678 SUMMARY OF INVENTION Technical Problem

The present inventors performed independent examination, and conceived of the idea that no prior art had developed refrigerant compositions having three types of performance, i.e., a refrigerating capacity (also referred to as “cooling capacity” or “capacity”) and a coefficient of performance (COP) that are equivalent to those of R410A, and a sufficiently low GWP. An object of the present disclosure is to solve this unique problem.

Solution to Problem Item 1

A composition comprising a refrigerant, the refrigerant comprising trans-1,2-difluoroethylene (HFO-1132(E)), trifluoroethylene (HFO-1123), and 2,3,3,3-tetrafluoro-1-propene (R1234yf).

Item 2

A composition comprising a refrigerant, the refrigerant comprising trans-1,2-difluoroethylene (HFO-1132(E)) and 2,3,3,3-tetrafluoro-1-propene (R1234yf), and optionally further comprising trifluoroethylene HFO-1123),

wherein

when the mass % of HFO-1132(E), HFO-1123, and R1234yf based on their sum in the refrigerant is respectively represented by x, y, and z, coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), HFO-1123, and R1234yf is 100 mass % are within the range of a figure surrounded by line segments OD, DG, GH, and HO that connect the following 4 points:

point D (87.6, 0.0, 12.4), point G (18.2, 55.1, 26.7), point H (56.7, 43.3, 0.0), and point O (100.0, 0.0, 0.0), or on the line segments OD, DG, and GH (excluding the points O and H);

the line segment DG is represented by coordinates (0.0047y²−1.5177y+87.598, y, −0.0047y²+0.5177y+12.402),

the line segment GH is represented by coordinates (−0.0134z²−1.0825z+56.692, 0.0134z²+0.0825z+43.308, z), and

the line segments HO and OD are straight lines.

Item 3

The composition according to Item 1,

wherein

when the mass % of HFO-1132(E), HFO-1123, and R1234yf based on their sum in the refrigerant is respectively represented by x, y, and z, coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), HFO-1123, and R1234yf is 100 mass % are within the range of a figure surrounded by line segments LG, GH, HI, and IL that connect the following 4 points:

point L (72.5, 10.2, 17.3), point G (18.2, 55.1, 26.7), point H (56.7, 43.3, 0.0), and point I (72.5, 27.5, 0.0), or on the line segments LG, GH, and IL (excluding the points H and I);

the line segment LG is represented by coordinates (0.0047y²−1.5177y+87.598, y, −0.0047y²+0.5177y+12.402),

the line segment GH is represented by coordinates (−0.0134 z²−1.0825z+56.692, 0.0134z²+0.0825z+43.308, z), and

the line segments HI and IL are straight lines.

Item 4

The composition according to any one of Items 1 to 3, further comprising R32.

Item 5

The composition according to Item 4,

wherein

when the mass % of HFO-1132(E), HFO-1123, R1234yf, and R32 based on their sum in the refrigerant is respectively represented by x, y, z, and a,

if 0<a≤10.0, coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), HFO-1123, and R1234yf is (100-a) mass % are within the range of a figure surrounded by straight lines that connect the following 4 points:

point A (0.02a²−2.46a+93.4, 0, −0.02a²+1.46a+6.6), point B′(−0.008a²−1.38a+56, 0.018a²−0.53a+26.3, −0.01a²+0.91a+17.7), point C (−0.016a²+0.02a+77.6, 0.016a²−1.02a+22.4, 0), and point O (100.0-a, 0.0, 0.0), or on the straight lines OA, AB′, and B′C (excluding the points O and C);

if 10.0<a≤16.5, coordinates (x,y,z) in the ternary composition diagram are within the range of a figure surrounded by straight lines that connect the following 4 points:

point A (0.0244a²−2.5695a+94.056, 0, −0.0244a²+1.5695a+5.944), point B′(0.0161a²−1.9959a+59.749, 0.014a²−0.3399a+24.8, −0.0301a²+1.3358a+15.451), point C (−0.0161a²−0.0041a+77.851, 0.0161a²−0.9959a+22.149, 0), and point O (100.0-a, 0.0, 0.0), or on the straight lines OA, AB′, and B′C (excluding the points O and C); or

if 16.5<a≤21.8, coordinates (x,y,z) in the ternary composition diagram are within the range of a figure surrounded by straight lines that connect the following 4 points:

point A (0.0161a²−2.3535a+92.742, 0, −0.0161a²+1.3535a+7.258), point B′(−0.0435a²−0.4456a+50.406, −0.0304a²+1.8991a−0.0661, 0.0739a²−2.4535a+49.6601), point C (−0.0263a²+0.3107a+75.444, 0.0263a²−1.3107a+24.556, 0), and point O (100.0-a, 0.0, 0.0), or on the straight lines OA, AB′, and B′C (excluding the points O and C).

Item 6

The composition according to any one of Items 1 to 5, for use as a working fluid for a refrigerating machine, wherein the composition further comprises a refrigeration oil.

Item 7

The composition according to any one of Items 1 to 6, for use as an alternative refrigerant for R410A.

Item 8

Use of the composition according to any one of Items 1 to 6 as an alternative refrigerant for R410A.

Item 9

A refrigerating machine comprising the composition according to any one of Items 1 to 6 as a working fluid.

Item 10

A method for operating a refrigerating machine, comprising the step of circulating the composition according to any one of Items 1 to 6 as a working fluid in a refrigerating machine.

Advantageous Effects of Invention

The refrigerant according to the present disclosure has three types of performance, i.e., a refrigerating capacity and a coefficient of performance that are equivalent to those of R410A, and a sufficiently low GWP.

BRIEF DESCRIPTION OF DRAWING

FIG. 1 is a schematic view of an apparatus used in a flammability test.

FIG. 2 is a diagram showing points A to M and O, and line segments that connect these points to each other in a ternary composition diagram in which the sum of HFO-1132(E), HFO-1123, and R1234yf is 100 mass %.

FIG. 3 is a diagram showing points A to C, B′ and O, and line segments that connect these points to each other in a ternary composition diagram in which the sum of HFO-1132(E), HFO-1123, and R1234yf is 100 mass %.

FIG. 4 is a diagram showing points A to C, B′ and O, and line segments that connect these points to each other in a ternary composition diagram in which the sum of HFO-1132(E), HFO-1123, and R1234yf is 95 mass % (R32 content is 5 mass %).

FIG. 5 is a diagram showing points A to C, B′ and O, and line segments that connect these points to each other in a ternary composition diagram in which the sum of HFO-1132(E), HFO-1123, and R1234yf is 90 mass % (R32 content is 10 mass %).

FIG. 6 is a diagram showing points A to C, B′ and O, and line segments that connect these points to each other in a ternary composition diagram in which the sum of HFO-1132(E), HFO-1123, and R1234yf is 85.7 mass % (R32 content is 14.3 mass %).

FIG. 7 is a diagram showing points A to C, B′ and O, and line segments that connect these points to each other in a ternary composition diagram in which the sum of HFO-1132(E), HFO-1123, and R1234yf is 83.5 mass % (R32 content is 16.5 mass %).

FIG. 8 is a diagram showing points A to C, B′ and O, and line segments that connect these points to each other in a ternary composition diagram in which the sum of HFO-1132(E), HFO-1123, and R1234yf is 80.8 mass % (R32 content is 19.2 mass %).

FIG. 9 is a diagram showing points A to C, B′ and O, and line segments that connect these points to each other in a ternary composition diagram in which the sum of HFO-1132(E), HFO-1123, and R1234yf is 78.2 mass % (R32 content is 21.8 mass %).

DESCRIPTION OF EMBODIMENTS

The present inventors conducted intensive study to solve the above problem, and consequently found that a mixed refrigerant comprising trans-1,2-difluoroethylene (HFO-1132(E)) and 2,3,3,3-tetrafluoro-1-propene (R1234yf), and optionally further comprising trifluoroethylene (HFO-1123) has the above properties.

The present disclosure has been completed as a result of further research based on this finding. The present disclosure includes the following embodiments.

Definition of Terms

In the present specification, the term “refrigerant” includes at least compounds that are specified in ISO 817 (International Organization for Standardization), and that are given a refrigerant number (ASHRAE number) representing the type of refrigerant with “R” at the beginning; and further includes refrigerants that have properties equivalent to those of such refrigerants, even though a refrigerant number is not yet given. Refrigerants are broadly divided into fluorocarbon compounds and non-fluorocarbon compounds in terms of the structure cf the compounds. Fluorocarbon compounds include chlorofluorocarbons (CFC), hydrochlorofluorocarbons (HCFC), and hydrofluorocarbons (HFC). Non-fluorocarbon compounds include propane (R290), propylene (R1270), butane (R600), isobutane (R600a), carbon dioxide (R744), ammonia (R717), and the like.

In the present specification, the phrase “composition comprising a refrigerant” at least includes (1) a refrigerant itself (including a mixture of refrigerants), (2) a composition that further comprises other components and that can be mixed with at least a refrigeration oil to obtain a working fluid for a refrigerating machine, and (3) a working fluid for a refrigerating machine containing a refrigeration oil. In the present specification, of these three embodiments, the composition (2) is referred to as a “refrigerant composition” so as to distinguish it from a refrigerant itself (including a mixture of refrigerants). Further, the working fluid for a refrigerating machine (3) is referred to as a “refrigeration oil-containing working fluid” so as to distinguish it from the “refrigerant composition.”

In the present specification, when the term “alternative” is used in a context in which the first refrigerant is replaced with the second refrigerant, the first type of “alternative” means that equipment designed for operation using the first refrigerant can be operated using the second refrigerant under optimum conditions, optionally with changes of only a few parts (at least one of the following: refrigeration oil, gasket, packing, expansion valve, dryer, and other parts) and equipment adjustment. In other words, this type of alternative means that the same equipment is operated with an alternative refrigerant. Embodiments of this type of “alternative” include “drop-in alternative,” “nearly drop-in alternative,” and “retrofit,” in the order in which the extent of changes and adjustment necessary for replacing the first refrigerant with the second refrigerant is smaller.

The term “alternative” also includes a second type of “alternative,” which means that equipment designed for operation using the second refrigerant is operated for the same use as the existing use with the first refrigerant by using the second refrigerant. This type of alternative means that the same use is achieved with an alternative refrigerant.

In the present specification, the term “refrigerating machine” refers to machines in general that draw heat from an object or space to make its temperature lower than the temperature of ambient air, and maintain a low temperature. In other words, refrigerating machines refer to conversion machines that gain energy from the outside to do work, and that perform energy conversion, in order to transfer heat from where the temperature is lower to where the temperature is higher.

In the present specification, a refrigerant having a “lower flammability” means that it is determined to be “Class 2L” according to the US ANSI/ASHRAE Standard 34-2013.

1. Refrigerant 1.1 Refrigerant Component

The refrigerant according to the present disclosure is a mixed refrigerant comprising trans-1,2-difluoroethylene (HFO-1132(E)), trifluoroethylene (HFO-1123), and 2,3,3,3-tetrafluoro-1-propene (R1234yf).

The refrigerant according to the present disclosure has various properties that are desirable as an R410A-alternative refrigerant, i.e., a refrigerating capacity and a coefficient of performance that are equivalent to those of R410A, and a sufficiently low GWP.

The refrigerant according to the present disclosure is a composition comprising HFO-1132(E) and R1234yf, and optionally further comprising HFO-1123, and may further satisfy the following requirements. This refrigerant also has various properties desirable as an alternative refrigerant for R410A; i.e., it has a refrigerating capacity and a coefficient of performance that are equivalent to those of R410A, and a sufficiently low GWP.

Requirements

When the mass % of HFO-1132(E), HFO-1123, and R1234yf based on their sum is respectively represented by x, y, and z,

coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), HFO-1123, and R1234yf is 100 mass % are within the range of a figure surrounded by line segments OD, DG, GH, and HO that connect the following 4 points:

point D (87.6, 0.0, 12.4), point G (18.2, 55.1, 26.7), point H (56.7, 43.3, 0.0), and point O (100.0, 0.0, 0.0), or on the line segments OD, DG, and GH (excluding the points O and H);

the line segment DG is represented by coordinates (0.0047y²−1.5177y+87.598, y, −0.0047y²+0.5177y+12.402),

the line segment GH is represented by coordinates (−0.0134z²−1.0825z+56.692, 0.0134z²+0.0825z+43.308, z), and

the lines HO and OD are straight lines.

When the requirements above are satisfied, the refrigerant according to the present disclosure has a refrigerating capacity ratio of 92.5% or more relative to that of R410A, and a COP ratio of 92.5% or more relative to that of R410A.

The refrigerant according to the present disclosure is preferably a refrigerant wherein

when the mass % of HFO-1132(E), HFO-1123, and R1234yf based on their sum is respectively represented by x, y, and z, coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), HFO-1123, and R1234yf is 100 mass % are within the range of a figure surrounded by line segments LG, GH, HI, and IL that connect the following 4 points:

point L (72.5, 10.2, 17.3), point G (18.2, 55.1, 26.7), point H (56.7, 43.3, 0.0), and point I (72.5, 27.5, 0.0), or on the line segments LG, GH, and IL (excluding the points H and I);

the line segment LG is represented by coordinates (0.0047y²−1.5177y+87.598, y, −0.0047y²+0.5177y+12.402),

the line segment GH is represented by coordinates (−0.0134z²−1.0825z+56.692, 0.0134z²+0.0825z+43.308, z), and

the line segments HI and IL are straight lines.

When the requirements above are satisfied, the refrigerant according to the present disclosure has a refrigerating capacity ratio of 92.5% or more relative to that of R410A, and a COP ratio of 92.5% or more relative to that of R410A; furthermore, the refrigerant has a lower flammability (Class 2L) according to the ASHRAE standard.

The refrigerant according to the present disclosure is preferably a refrigerant wherein

when the mass % of HFO-1132(E), HFO-1123, and R1234yf based on their sum is respectively represented by x, y, and z, coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), HFO-1123, and R1234yf is 100 mass % are within the range of a figure surrounded by line segments OD, DE, EF, and FO that connect the following 4 points:

point D (87.6, 0.0, 12.4), point E (31.1, 42.9, 26.0), point F (65.5, 34.5, 0.0), and point O (100.0, 0.0, 0.0), or on the line segments OD, DE, and EF (excluding the points O and F);

the line segment DE is represented by coordinates (0.0047y²−1.5177y+87.598, y, −0.0047y²+0.5177y+12.402),

the line segment EF is represented by coordinates (−0.0064z²−1.1565z+65.501, 0.0064z²+0.1565z+34.499, z), and

the line segments FO and OD are straight lines.

When the requirements above are satisfied, the refrigerant according to the present disclosure has a refrigerating capacity ratio of 93.5% or more relative to that of R410A, and a COP ratio of 93.5% or more relative to that of R410A.

The refrigerant according to the present disclosure is preferably a refrigerant wherein

when the mass % of HFO-1132(E), HFO-1123, and R1234yf based on their sum is respectively represented by x, y, and z,

coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), HFO-1123, and R1234yf is 100 mass % are within the range of a figure surrounded by line segments LE, EF, FI, and IL that connect the following 4 points:

point L (72.5, 10.2, 17.3), point E (31.1, 42.9, 26.0), point F (65.5, 34.5, 0.0), and point I (72.5, 27.5, 0.0), or on the line segments LE, EF, and IL (excluding the points F and I);

the line segment LE is represented by coordinates (0.0047y²−1.5177y+87.598, y, −0.0047y²+0.5177y+12.402),

the line segment EF is represented by coordinates (−0.0134z²−1.0825z+56.692, 0.0134z²+0.0825z+43.308, z), and

the line segments FI and IL are straight lines.

When the requirements above are satisfied, the refrigerant according to the present disclosure has a refrigerating capacity ratio of 93.5% or more relative to that of R410A, and a COP ratio of 93.5% or more relative to that of R410A; furthermore, the refrigerant has a lower flammability (Class 2L) according to the ASHRAE standard.

The refrigerant according to the present disclosure is preferably a refrigerant wherein

when the mass % of HFO-1132(E), HFO-1123, and R1234yf based on their sum is respectively represented by x, y, and z,

coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), HFO-1123, and R1234yf is 100 mass % are within a figure surrounded by line segments CA, AB, BC, and CO that connect the following 4 points:

point A (93.4, 0.0, 6.6), point B (55.6, 26.6, 17.8), point C (77.6, 22.4, 0.0), and point O (100.0, 0.0, 0.0), or on the line segments OA, AB, and BC (excluding the points O and C);

the line segment AB is represented by coordinates (0.0052y²−1.5588y+93.385, y, −0.0052y²+0.5588y+6.615),

the line segment BC is represented by coordinates (−0.0032z²−1.1791z+77.593, 0.0032z²+0.1791z+22.407, z), and

the line segments CO and OA are straight lines.

When the requirements above are satisfied, the refrigerant according to the present disclosure has a refrigerating capacity ratio of 95% or more relative to that of R410A, and a COP ratio of 95% or more relative to that of R410A.

The refrigerant according to the present disclosure is preferably a refrigerant wherein

when the mass % of HFO-1132(E), HFO-1123, and R1234yf based on their sum is respectively represented by x, y, and z,

coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), HFO-1123, and R1234yf is 100 mass % are within a figure surrounded by line segments KB, BJ, and JK that connect the following 3 points:

point K (72.5, 14.1, 13.4), point B (55.6, 26.6, 17.8), and point J (72.5, 23.2, 4.3), or on the line segments KB, BJ, and JK;

the line segment KB is represented by coordinates (0.0052y²−1.5588y+93.385, y, and −0.0052y²+0.5588y+6.615),

the line segment BJ is represented by coordinates (−0.0032z²−1.1791z+77.593, 0.0032z²+0.1791z+22.407, z), and

the line segment JK is a straight line.

When the requirements above are satisfied, the refrigerant according to the present disclosure has a refrigerating capacity ratio of 95% or more relative to that of R410A, and a COP ratio of 95% or more relative to that of R410A; furthermore, the refrigerant has a lower flammability (Class 2L) according to the ASHRAE standard.

The refrigerant according to the present disclosure may further comprise difluoromethane (R32) in addition to HFO-1132(E), HFO-1123, and R1234yf as long as the above properties and effects are not impaired. The content of R32 based on the entire refrigerant according to the present disclosure is not particularly limited and can be selected from a wide range. For example, when the R32 content of the refrigerant according to the present disclosure is 21.8 mass %, the mixed refrigerant has a GWP of 150. Therefore, the R32 content can be 21.8 mass % or less. The R32 content of the refrigerant according to the present disclosure may be, for example, 5 mass % or more, based on the entire refrigerant.

When the refrigerant according to the present disclosure further contains R32 in addition to HFO-1132(E), HFO-1123, and R1234yf, the refrigerant may be a refrigerant wherein

when the mass % of HFO-1132(E), HFO-1123, R1234yf, and R32 based on their sum is respectively represented by x, y, z, and a,

if 0<a≤10.0, coordinates (x,y,z) in a ternary composition diagram (FIGS. 3 to 9) in which the sum of HFO-1132(E), HFO-1123, and R1234yf is (100-a) mass % are within the range of a figure surrounded by straight lines that connect the following 4 points:

point A (0.02a²−2.46a+93.4, 0, −0.02a²+1.46a+6.6), point B′(−0.008a²−1.38a+56, 0.018a²−0.53a+26.3, −0.01a²+0.91a+17.7), point C (−0.016a²+0.02a+77.6, 0.016a²−1.02a+22.4, 0), and point O (100.0-a, 0.0, 0.0), or on the straight lines OA, AB′, and B′C (excluding the points O and C);

if 10.0<a≤16.5, coordinates (x,y,z) in the ternary composition diagram are within the range of a figure surrounded by straight lines that connect the following 4 points:

point A (0.0244a²−2.5695a+94.056, 0, −0.0244a²+1.5695a+5.944), point B′(0.0161a²−1.9959a+59.749, 0.014a²−0.3399a+24.8, −0.0301a²+1.3358a+15.451), point C (−0.0161a²−0.0041a+77.851, 0.0161a²−0.9959a+22.149, 0), and point O (100.0-a, 0.0, 0.0), or on the straight lines OA, AB′, and B′C (excluding the points O and C); or

if 16.5<a≤21.8, coordinates (x,y,z) in the ternary composition diagram are within the range of a figure surrounded by straight lines that connect the following 4 points:

point A (0.0161a²−2.3535a+92.742, 0, −0.0161a²+1.3535a+7.258), point B′(−0.0435a²−0.4456a+50.406, −0.0304a²+1.8991a−0.0661, 0.0739a²−2.4535a+49.6601), point C (−0.0263a²+0.3107a+75.444, 0.0263a²−1.3107a+24.556, 0), and point O (100.0-a, 0.0, 0.0), or on the straight lines OA, AB′, and B′C (excluding the points O and C). Note that when point B in the ternary composition diagram is defined as a point where a refrigerating capacity ratio of 95% relative to that of R410A and a COP ratio of 95% relative to that of R410A are both achieved, point B′ is the intersection of straight line AB and an approximate line formed by connecting the points where the COP ratio relative to that of R410A is 95%. When the requirements above are satisfied, the refrigerant according to the present disclosure has a refrigerating capacity ratio of 95% or more relative to that of R410A, and a COP ratio of 95% or more relative to that of R410A.

The refrigerant according to the present disclosure may further comprise other additional refrigerants in addition to HFO-1132(E), HFO-1123, R1234yf, and R32 as long as the above properties and effects are not impaired. In this respect, the refrigerant according to the present disclosure preferably comprises HFO-1132(E), HFO-1123, R1234yf, and R32 in a total amount of 99.5 mass % or more, more preferably 99.75 mass % or more, and still more preferably 99.9 mass % or more, based on the entire refrigerant.

The refrigerant according to the present disclosure may comprise HFO-1132(E), HFO-1123, and R1234yf in a total amount of 99.5 mass % or more, 99.75 mass % or more, or 99.9 mass % or more, based on the entire refrigerant.

The refrigerant according to the present disclosure may comprise HFO-1132(E), HFO-1123, R1234yf, and R32 in a total amount of 99.5 mass % or more, 99.75 mass % or more, or 99.9 mass % or more, based on the entire refrigerant.

Additional refrigerants are not particularly limited and can be widely selected. The mixed refrigerant may contain one additional refrigerant, or two or more additional refrigerants.

1.2. Use

The refrigerant according to the present disclosure can be preferably used as a working fluid in a refrigerating machine.

The composition according to the present disclosure is suitable for use as an alternative refrigerant for R410A.

2. Refrigerant Composition

The refrigerant composition according to the present disclosure comprises at least the refrigerant according to the present disclosure, and can be used for the same use as the refrigerant according to the present disclosure. Moreover, the refrigerant composition according to the present disclosure can be further mixed with at least a refrigeration oil to thereby obtain a working fluid for a refrigerating machine.

The refrigerant composition according to the present disclosure further comprises at least one other component in addition to the refrigerant according to the present disclosure. The refrigerant composition according to the present disclosure may comprise at least one of the following other components, if necessary. As described above, when the refrigerant composition according to the present disclosure is used as a working fluid in a refrigerating machine, it is generally used as a mixture with at least a refrigeration oil. Therefore, it is preferable that the refrigerant composition according to the present disclosure does not substantially comprise a refrigeration oil. Specifically, in the refrigerant composition according to the present disclosure, the content of the refrigeration oil based on the entire refrigerant composition is preferably 0 to 1 mass %, and more preferably 0 to 0.1 mass %.

2.1. Water

The refrigerant composition according to the present disclosure may contain a small amount of water. The water content of the refrigerant composition is preferably 0.1 mass % or less based on the entire refrigerant. A small amount of water contained in the refrigerant composition stabilizes double bonds in the molecules of unsaturated fluorocarbon compounds that can be present in the refrigerant, and makes it less likely that the unsaturated fluorocarbon compounds will be oxidized, thus increasing the stability of the refrigerant composition.

2.2. Tracer

A tracer is added to the refrigerant composition according to the present disclosure at a detectable concentration such that when the refrigerant composition has been diluted, contaminated, or undergone other changes, the tracer can trace the changes.

The refrigerant composition according to the present disclosure may comprise a single tracer, or two or more tracers.

The tracer is not limited, and can be suitably selected from commonly used tracers.

Examples of tracers include hydrofluorocarbons, hydrochlorofluorocarbons, chlorofluorocarbons, hydrochlorocarbons, fluorocarbons, deuterated hydrocarbons, deuterated hydrofluorocarbons, perfluorocarbons, fluoroethers, brominated compounds, iodinated compounds, alcohols, aldehydes, ketones, and nitrous oxide (N₂O). The tracer is particularly preferably a hydrofluorocarbon, a hydrochlorofluorocarbon, a chlorofluorocarbon, a hydrochlorocarbon, a fluorocarbon, or a fluoroether.

The following compounds are preferable as the tracer.

FC-14 (tetrafluoromethane, CF₄) HCC-40 (chloromethane, CH₃Cl) HFC-23 (trifluoromethane, CHF₃) HFC-41 (fluoromethane, CH₃Cl) HFC-125 (pentafluoroethane, CF₃CHF₂) HFC-134a (1,1,1,2-tetrafluoroethane, CF₃CH₂F) HFC-134 (1,1,2,2-tetrafluoroethane, CHF₂CHF₂) HFC-143a (1,1,1-trifluoroethane, CF₃CH₃) HFC-143 (1,1,2-trifluoroethane, CHF₂CH₂F) HFC-152a (1,1-difluoroethane, CHF₂CH₃) HFC-152 (1,2-difluoroethane, CH₂FCH₂F) HFC-161 (fluoroethane, CH₃CH₂F) HFC-245fa (1,1,1,3,3-pentafluoropropane, CF₃CH₂CHF₂) HFC-236fa (1,1,1,3,3,3-hexafluoropropane, CF₃CH₂CF₃) HFC-236ea (1,1,1,2,3,3-hexafluoropropane, CF₃CHFCHF₂) HFC-227ea (1,1,1,2,3,3,3-heptafluoropropane, CF₃CHFCF₃) HCFC-22 (chlorodifluoromethane, CHClF₂) HCFC-31 (chlorofluoromethane, CH₂ClF) CFC-1113 (chlorotrifluoroethylene, CF₂═CClF) HFE-125 (trifluoromethyl-difluoromethyl ether, CF₃OCHF₂) HFE-134a (trifluoromethyl-fluoromethyl ether, CF₃OCH₂F) HFE-143a (trifluoromethyl-methyl ether, CF₃OCH₃) HFE-227ea (trifluoromethyl-tetrafluoroethyl ether, CF₃OCHFCF₃) HFE-236fa (trifluoromethyl-trifluoroethyl ether, CF₃OCH₂CF₃)

The refrigerant composition according to the present disclosure may contain one or more tracers at a total concentration of about 10 parts per million by weight (ppm) to about 1000 ppm based on the entire refrigerant composition. The refrigerant composition according to the present disclosure may preferably contain one or more tracers at a total concentration of about 30 ppm to about 500 ppm, and more preferably about 50 ppm to about 300 ppm, based on the entire refrigerant composition.

2.3. Ultraviolet Fluorescent Dye

The refrigerant composition according to the present disclosure may comprise a single ultraviolet fluorescent dye, or two or more ultraviolet fluorescent dyes.

The ultraviolet fluorescent dye is not limited, and can be suitably selected from commonly used ultraviolet fluorescent dyes.

Examples of ultraviolet fluorescent dyes include naphthalimide, coumarin, anthracene, phenanthrene, xanthene, thioxanthene, naphthoxanthene, fluorescein, and derivatives thereof. The ultraviolet fluorescent dye is particularly preferably either naphthalimide or coumarin, or both.

2.4. Stabilizer

The refrigerant composition according to the present disclosure may comprise a single stabilizer, or two or more stabilizers.

The stabilizer is not limited, and can be suitably selected from commonly used stabilizers.

Examples of stabilizers include nitro compounds, ethers, and amines.

Examples of nitro compounds include aliphatic nitro compounds, such as nitromethane and nitroethane; and aromatic nitro compounds, such as nitro benzene and nitro styrene.

Examples of ethers include 1,4-dioxane.

Examples of amines include 2,2,3,3,3-pentafluoropropylamine and diphenylamine.

Examples of stabilizers also include butylhydroxyxylene and benzotriazole.

The content of the stabilizer is not limited. Generally, the content of the stabilizer is preferably 0.01 to 5 mass %, and more preferably 0.05 to 2 mass %, based on the entire refrigerant.

2.5. Polymerization Inhibitor

The refrigerant composition according to the present disclosure may comprise a single polymerization inhibitor, or two or more polymerization inhibitors.

The polymerization inhibitor is not limited, and can be suitably selected from commonly used polymerization inhibitors.

Examples of polymerization inhibitors include 4-methoxy-1-naphthol, hydroquinone, hydroquinone methyl ether, dimethyl-t-butylphenol, 2,6-di-tert-butyl-p-cresol, and benzotriazole.

The content of the polymerization inhibitor is not limited. Generally, the content of the polymerization inhibitor is preferably 0.01 to 5 mass %, and more preferably 0.05 to 2 mass %, based on the entire refrigerant.

3. Refrigeration Oil-Containing Working Fluid

The refrigeration oil-containing working fluid according to the present disclosure comprises at least the refrigerant or refrigerant composition according to the present disclosure and a refrigeration oil, for use as a working fluid in a refrigerating machine. Specifically, the refrigeration oil-containing working fluid according to the present disclosure is obtained by mixing a refrigeration oil used in a compressor of a refrigerating machine with the refrigerant or the refrigerant composition. The refrigeration oil-containing working fluid generally comprises 10 to 50 mass % of refrigeration oil.

3.1. Refrigeration Oil

The composition according to the present disclosure may comprise a single refrigeration oil, or two or more refrigeration oils.

The refrigeration oil is not limited, and can be suitably selected from commonly used refrigeration oils. In this case, refrigeration oils that are superior in the action of increasing the miscibility with the mixture and the stability of the mixture, for example, are suitably selected as necessary.

The base oil of the refrigeration oil is preferably, for example, at least one member selected from the group consisting of polyalkylene glycols (PAG), polyol esters (POE), and polyvinyl ethers (PVE).

The refrigeration oil may further contain additives in addition to the base oil. The additive may be at least one member selected from the group consisting of antioxidants, extreme-pressure agents, acid scavengers, oxygen scavengers, copper deactivators, rust inhibitors, oil agents, and antifoaming agents.

A refrigeration oil with a kinematic viscosity of 5 to 400 cSt at 40° C. is preferable from the standpoint of lubrication.

The refrigeration oil-containing working fluid according to the present disclosure may further optionally contain at least one additive. Examples of additives include compatibilizing agents described below.

3.2. Compatibilizing Agent

The refrigeration oil-containing working fluid according to the present disclosure may comprise a single compatibilizing agent, or two or more compatibilizing agents.

The compatibilizing agent is not limited, and can be suitably selected from commonly used compatibilizing agents.

Examples of compatibilizing agents include polyoxyalkylene glycol ethers, amides, nitriles, ketones, chlorocarbons, esters, lactones, aryl ethers, fluoroethers, and 1,1,1-trifluoroalkanes. The compatibilizing agent is particularly preferably a polyoxyalkylene glycol ether.

4. Method for Operating Refrigerating Machine

The method for operating a refrigerating machine according to the present disclosure is a method for operating a refrigerating machine using the refrigerant according to the present disclosure.

Specifically, the method for operating a refrigerating machine according to the present disclosure comprises the step of circulating the refrigerant according to the present disclosure in a refrigerating machine.

The embodiments are described above; however, it will be understood that various changes in forms and details can be made without departing from the spirit and scope of the claims.

EXAMPLES

The present disclosure is described in more detail below with reference to Examples. However, the present disclosure is not limited to the Examples.

Mixed refrigerants were prepared by mixing HFO-1132(E), HFO-1123, and R1234yf at mass % based on their sum shown in Tables 1 to 5.

The COP ratio and the refrigerating capacity ratio of the mixed refrigerants relative to those of R410 were determined. The calculation conditions were as follows.

Evaporating temperature: 5° C.

Condensation temperature: 45° C.

Degree of superheating: 1 K

Degree of subcooling: 5 K

E_(comp) (compressive modulus): 0.7 kWh

Tables 1 to 5 show these values together with the GWP of each mixed refrigerant.

TABLE 1 Comp. Example Example Example Example Example Example Item Unit Ex. 1 1 A 2 3 4 5 6 B HFO-1132(E) mass % R410A 93.4 85.7 78.3 71.2 64.3 55.6 HFO-1123 mass % 0.0 5.0 10.0 15.0 20.0 26.6 R1234yf mass % 6.6 9.3 11.7 13.8 15.7 17.8 GWP — 2088 1 1 1 1 1 2 COP ratio % (relative 100 98.0 97.5 96.9 96.3 95.8 95.0 to R410A) Refrigerating % (relative 100 95.0 95.0 95.0 95.0 95.0 95.0 capacity ratio to R410A)

TABLE 2 Comp. Ex. 2 Example Example Example item Unit C 7 8 9 HFO-1132(E) mass % 77.6 71.6 65.5 59.2 HFO-1123 mass % 22.4 23.4 24.5 25.8 R1234yf mass % 0.0 5.0 10.0 15.0 GWP — 1 1 1 1 COP ratio % (relative 95.0 95.0 95.0 95.0 to R410A) Refrigerating % (relative 102.5 100.5 98.4 96.3 capacity ratio to R410A)

TABLE 3 Example Example Example Example Example Example Example Item Unit 10 D 11 12 13 14 15 16 G HFO-1132(E) mass % 87.6 72.9 59.1 46.3 34.4 23.5 18.2 HFO-1123 mass % 0.0 10.0 20.0 30.0 40.0 50.0 55.1 R1234yf mass % 12.4 17.1 20.9 23.7 25.6 26.5 26.7 GWP — 1 2 2 2 2 2 2 COP ratio % (relative 98.2 97.1 95.9 94.8 93.8 92.9 92.5 to R410A) Refrigerating % (relative 92.5 92.5 92.5 92.5 92.5 92.5 92.5 capacity ratio to R410A)

TABLE 4 Comp. Example Example Comp. Example Example Example Item Unit Ex. 3 H 17 18 Ex. 4 F 19 20 21 E HFO-1132(E) mass % 56.7 44.5 29.7 65.5 53.3 39.8 31.1 HFO-1123 mass % 43.3 45.5 50.3 34.5 36.7 40.2 42.9 R1234yf mass % 0.0 10.0 20.0 0.0 10.0 20.0 26.0 GWP — 1 1 2 1 1 2 2 COP ratio % (relative 92.5 92.5 92.5 93.5 93.5 93.5 93.5 to R410A) Refrigerating % (relative 105.8 101.2 96.2 104.5 100.2 95.5 92.5 capacity ratio to R410A)

TABLE 5 Comp. Example Example Example Comp. Ex. 5 22 23 24 Ex. 6 Item Unit I J K L M HFO-1132(E) mass % 72.5 72.5 72.5 72.5 72.5 HFO-1123 mass % 27.5 23.2 14.1 10.2 0.0 R1234yf mass % 0.0 4.3 13.4 17.3 27.5 GWP — 1 1 1 2 2 COP ratio % (relative 94.4 95.0 96.4 97.1 98.8 to R410A) Refrigerating % (relative 103.5. 100.8 95.0 92.5 85.7 capacity ratio to R410A)

These results indicate that under the condition that the mass % of HFO-1132(E), HFO-1123, and R1234yf based on their sum is respectively represented by x, y, and z, when coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), HFO-1123, and R1234yf is 100 mass % are within the range of a figure (FIG. 2) surrounded by line segments OD, DG, GH, and HO that connect the following 4 points:

point D (87.6, 0.0, 12.4), point G (18.2, 55.1, 26.7), point H (56.7, 43.3, 0.0), and point O (100.0, 0.0, 0.0), or on the line segments OD, DG, and GH (excluding the points O and H), the refrigerant has a refrigerating capacity ratio of 92.5% or more relative to that of R410A, and a COP ratio of 92.5% or more relative to that of R410A.

Likewise, the results indicate that when coordinates (x,y,z) are within the range of a figure (FIG. 2) surrounded by line segments OD, DE, EF, and FO that connect the following 4 points:

point D (87.6, 0.0, 12.4), point E (31.1, 42.9, 26.0), point F (65.5, 34.5, 0.0), and point O (100.0, 0.0, 0.0), or on the line segments OD, DE, and EF (excluding the points O and F), the refrigerant has a refrigerating capacity ratio of 93.5% or more relative to that of R410A, and a COP ratio of 93.5% or more relative to that of R410A.

Likewise, the results indicate that when coordinates (x,y,z) are within the range of a figure (FIG. 2) surrounded by line segments OA, AB, BC, and CO that connect the following 4 points:

point A (93.4, 0.0, 6.6), point B (55.6, 26.6, 17.8), point C (77.6, 22.4, 0.0), and point O (100.0, 0.0, 0.0), or on the line segments OA, AB, and BC (excluding the points O and C), the refrigerant has a refrigerating capacity ratio of 95% or more relative to that of R410A, and a COP ratio of 95% or more relative to that of R410A.

R1234yf contributes to reduction of flammability and deterioration of polymerization etc. in these compositions. Therefore, the composition according to the present disclosure preferably contains R1234yf.

Further, the burning velocity of these mixed refrigerants was measured according to the ANSI/ASHRAE Standard 34-2013. Compositions that showed a burning velocity cf 10 cm/s or less were determined to be Class 2L (lower flammability). These results clearly indicate that when the content cf HFO-1132(E) in a mixed refrigerant of HFO-1132(E), HFO-1123, and R1234yf is 72.5 mass % or less based on their sum, the refrigerant can be determined to be Class 2L (lower flammability).

A burning velocity test was performed using the apparatus shown in FIG. 1 in the following manner. First, the mixed refrigerants used had a purity of 99.5% or more, and were degassed by repeating a cycle of freezing, pumping, and thawing until no traces of air were observed on the vacuum gauge. The burning velocity was measured by the closed method. The initial temperature was ambient temperature. Ignition was performed by generating an electric spark between the electrodes in the center of a sample cell. The duration of the discharge was 1.0 to 9.9 ms, and the ignition energy was typically about 0.1 to 1.0 J. The spread of the flame was visualized using schlieren photographs. A cylindrical container (inner diameter: 155 mm, length: 198 mm) equipped with two light transmission acrylic windows was used as the sample cell, and a xenon lamp was used as the light source. Schlieren images of the flame were recorded by a high-speed digital video camera at a frame rate of 600 fps and stored on a PC.

Mixed refrigerants were prepared by mixing HFO-1132(E), HFO-1123, R1234yf, and R32 in amounts shown in Tables 6 to 12, in terms of mass %, based on their sum.

The COP ratio and the refrigerating capacity ratio of these mixed refrigerants relative to those of R410A were determined. The calculation conditions were the same as described above. Tables 6 to 12 show these values together with the GWP of each mixed refrigerant.

TABLE 6 Comp. Comp. Comp. Comp. Example Comp. Example Example Comp. Ex. Item Unit Ex. 1 Ex. 7 A Ex. 8 Ex. 9 25 B′ Ex. 10 B 26 27 11 C HFO-1132(E) mass % R410A 93.4 78.3 64.3 56.0 55.6 60.0 70.0 77.6 HFO-1123 mass % 0.0 10.0 20.0 26.3 26.6 25.6 23.7 22.4 R1234yf mass % 6.6 11.7 15.7 17.7 17.8 14.4 6.3 0.0 R32 mass % 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 GWP — 2088 1.2 1.4 1.5 1.5 1.5 1.4 1.2 1.0 COP ratio % (relative 100 98.0 96.9 95.8 95.0 95.0 95.0 95.0 95.0 to R410A) Refrigerating % (relative 100 95.0 95.0 95.0 95.0 95.0 96.5 100.0 102.5 capacity ratio to R410A)

TABLE 7 Comp. Comp. Comp. Example Comp. Example Example Comp. Ex. Item Unit Ex. 12 A Ex. 13 Ex. 14 28 B′ Ex. 15 B 29 30 16 C HFO-1132(E) mass % 81.6 67.3 53.9 48.9 47.2 60.0 70.0 77.3 HFO-1123 mass % 0.0 10.0 20.0 24.1 25.3 21.6 19.2 17.7 R1234yf mass % 13.4 17.7 21.1 22.0 22.5 13.4 5.8 0.0 R32 mass % 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 GWP — 35 35 35 35 35 35 35 35 COP ratio % (relative 97.6 96.6 95.5 95.0 95.0 95.0 95.0 95.0 to R410A) Refrigerating % (relative 95.0 95.0 95.0 104.4 95.0 99.0 102.1 104.4 capacity ratio to R410A)

TABLE 8 Comp. Comp. Comp. Example Comp. Example Example Comp. Ex. Item Unit Ex. 17 A Ex. 18 Ex. 19 31 B′ Ex. 20 B 32 33 21 C HFO-1132(E) mass % 70.8 57.2 44.5 41.4 36.4 60.0 70.0 76.2 HFO-1123 mass % 0.0 10.0 20.0 22.8 26.7 18.0 15.3 13.8 R1234yf mass % 19.2 22.8 25.5 25.8 26.9 12.0 4.7 0.0 R32 mas s% 10.0 10.0 10.0 10.0 10.0 10.0 10.0 10.0 GWP — 69 69 69 69 69 69 69 68 COP ratio % (relative 97.4 96.5 95.6 95.0 95.0 95.0 95.0 95.0 to R4104) Refrigerating % (relative 95.0 95.0 95.0 106.2 95.0 101.5 104.4 106.2 capacity ratio to R410A)

TABLE 9 Comp. Comp. Comp. Example Comp. Example Example Comp. Ex Item Unit Ex. 22 A Ex. 23 Ex. 24 34 B′ Ex. 25 B 35 36 26 C HFO-1132(E) mass % 62.3 49.3 37.1 34.5 24.9 60.0 70.0 74.5 HFO-1123 mass % 0.0 10.0 20.0 22.8 30.7 15.4 12.4 11.2 R1234yf mass % 23.4 26.4 28.6 28.4 30.1 10.3 3.3 0.0 R32 mass % 14.3 14.3 14.3 14.3 14.3 14.3 14.3 14.3 GWP — 98 98 98 98 98 98 97 97 COP ratio % (relative 97.3 96.5 95.7 95.5 95.0 95.0 95.0 95.0 to R410A) Refrigerating % (relative 95.0 95.0 95.0 95.4 95.0 103.7 106.5 107.7 capacity ratio to R410A)

TABLE 10 Comp. Comp. Comp. Example Comp. Example Example Comp. Ex. Item Unit Ex. 27 A Ex. 28 Ex. 29 37 B′ Ex. 30 B 38 39 31 C HFO-1132(E) mass % 58.3 45.5 33.5 31.2 16.5 60.0 70.0 73.4 HFO-1123 mass % 0.0 10.0 20.0 23.0 35.5 14.2 11.1 10.1 R1234yf mass % 25.2 28.0 30.0 29.3 31.5 9.3 2.4 0.0 R32 mass % 16.5 16.5 16.5 16.5 16.5 16.5 16.5 16.5 GWP — 113.0 113.1 113.1 113.1 113.2 112.5 112.3 112.2 COP ratio % (relative 97.4 96.6 95.9 95.6 95.0 95.0 95.0 95.0 to R410A) Refrigerating % (relative 95.0 95.0 95.0 95.7 95.0 104.9 107.6 108.5 capacity ratio to R410A)

TABLE 11 Comp. Comp. Comp. Example Comp. Example Example Comp. Ex. Item Unit Ex. 32 A Ex. 33 Ex. 34 40 B′ Ex. 35 B 41 42 36 C HFO-1132(E) mass % 53.5 41.0 29.3 25.8 0.0 50.0 60.0 71.7 HFO-1123 mass % 0.0 10.0 20.0 25.2 48.8 16.8 12.9 9.1 R1234yf mass % 27.3 29.8 31.5 29.8 32.0 14.0 7.9 0.0 R32 mass % 19.2 19.2 19.2 19.2 19.2 19.2 19.2 19.2 GWP — 131.2 131.3 131.4 131.3 131.4 130.8 130.6 130.4 COP ratio % (relative 97.4 96.7 96.1 97.8 95.0 95.0 95.0 95.0 to R410) Refrigerating % (relative 95.0 95.0 95.0 96.3 95.0 104.0 106.4 109.4 capacity ratio to R410A)

TABLE 12 Comp. Comp. Comp. Example Comp. Example Example Comp. Ex. Item Unit Ex. 37 A Ex. 38 Ex. 39 43 B′ Ex. 40 B 44 45 41 C HFO-1132(E) mass % 49.1 36.9 25.5 20.0 0.0 50.0 60.0 69.7 HFO-1123 mass % 0.0 10.0 20.0 26.9 45.3 15.8 11.9 8.5 R1234yf mass % 29.1 31.3 20.0 31.3 32.9 12.4 63 0.0 R32 mass % 21.8 21.8 21.8 21.8 21.8 21.8 21.8 21.8 GWP — 148.8 148.9 148.9 148.9 148.9 148.3 148.1 147.9 COP ratio % (relative 97.6 96.9 96.4 95.9 95.5 95.0 95.0 95.0 to R410 Refrigerating % (relative 95.0 95.0 95.0 98.4 95.0 105.6 108.0 110.3 capacity ratio to R410A)

These results indicate that the refrigerants according to the present disclosure that satisfy the following conditions have a refrigerating capacity ratio of 95% or more relative to that of R410A, and a COP ratio of 95% or more relative to that of R410A:

when the mass % of HFO-1132(E), HFO-1123, R1234yf, and R32 based on their sum is respectively represented by x, y, z, and a,

if 0<a≤1.0.0, coordinates (x,y,z) in a ternary composition diagram (FIGS. 3 to 9) in which the sum of HFO-1132(E), HFO-1123, and R1234yf is (100-a) mass % are within the range of a figure surrounded by straight lines that connect the following 4 points:

point A (0.02a²−2.46a+93.4, 0, −0.02a²+1.46a+6.6), point B′(−0.008a²−1.38a+56, 0.018a²−0.53a+26.3, −0.01a²+0.91a+17.7), point C (−0.016a²+0.02a+77.6, 0.016a²−1.02a+22.4, 0), and point O (100.0-a, 0.0, 0.0), or on the straight lines OA, AB′, and B′C (excluding the points O and C);

if 10.0<a≤16.5, coordinates (x,y,z) in the ternary composition diagram are within the range of a figure surrounded by straight lines that connect the following 4 points:

point A (0.0244a²−2.5695a+94.056, 0, −0.0244a²+1.5695a+5.944), point B′(0.0161a²−1.9959a+59.749, 0.014a²−0.3399a+24.8, −0.0301a²+1.3358a+15.451), point C (−0.0161a²−0.0041a+77.851, 0.0161a²−0.9959a+22.149, 0), and point O (100.0-a, 0.0, 0.0), or on the straight lines OA, AB′, and B′C (excluding the points O and C); or

if 16.5<a≤21.8, coordinates (x,y,z) in the ternary composition diagram are within the range of a figure surrounded by straight lines that connect the following 4 points:

point A (0.0161a²−2.3535a+92.742, 0, −0.0161a²+1.3535a+7.258), point B′(−0.0435a²−0.4456a+50.406, −0.0304a²+1.8991a−0.0661, 0.0739a²−2.4535a+49.6601), point C (−0.0263a²+0.3107a+75.444, 0.0263a²−1.3107a+24.556, 0), and point O (100.0-a, 0.0, 0.0), or on the straight lines OA, AB′, and B′C (excluding the points O and C).

FIGS. 3 to 9 show compositions whose R32 content a (mass %) is 0 mass %, 5 mass %, 10 mass %, 14.3 mass %, 16.5 mass %, 19.2 mass %, and 21.8 mass %, respectively.

Note that when point B in the ternary composition diagram is defined as a point where a refrigerating capacity ratio of 95% relative to that of R410A and a COP ratio of 95% relative to that of R410A are both achieved, point B′ is the intersection of straight line AB and an approximate line formed by connecting three points, including point C, where the COP ratio relative to that of R410A is 95%.

Points A, B′, and C were individually obtained by approximate calculation in the following manner.

Point A is a point where the HFO-1123 content is 0 mass % and a refrigerating capacity ratio of 95% relative to that of R410A is achieved. Three points corresponding to point A were obtained in each of the following three ranges by calculation, and their approximate expressions were obtained.

TABLE 13 Item 10.0 ≥ R32 ≥ 0 16.5 ≥ R32 ≥ 10.0 21.8 ≥ R32 ≥ 16.5 R32 0.0 5.0 10.0 10.0 14.3 16.5 16.5 19.2 21.8 HFO-1132(E) 93.4 81.6 70.8 70.8 62.3 58.3 58.3 53.5 49.1 HFO-1123 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 R1234yf 6.6 13.4 19.2 192 23.4 25.2 25.2 27.3 29.1 R32 A a a HFO-1132(E) 0.02a2 − 2.46a + 93.4 0.0244a2 − 2.5695a + 94.056 0.0161a2 − 2.3535a + 92.742 approximate expression HFO-1123 0 0 0 approximate expression R1234yf 100 − R32 − HFO − 1132(E) 100 − R32 − HFO − 1132(E) 100 − R32 − HFO − 1132(E) approximate expression

Point C is a point where the R1234yf content is 0 mass % and a COP ratio of 95% relative to that of R410A is achieved. Three points corresponding to point C were obtained in each of the following three ranges by calculation, and their approximate expressions were obtained.

TABLE 14 Item 10.0 ≥ R32 ≥ 0 16.5 ≥ R32 ≥ 10.0 21.8 ≥ R32 ≥ 16.5 R32 0 5 10 10 14.3 16.5 16.5 19.2 21.8 HFO-1132(E) 77.6 77.3 76.2 76.2 74.5 73.4 73.4 71.7 69.7 HFO-1123 22.4 17.7 13.8 13.8 11.2 10.1 10.1 9.1 8.5 R1234yf 0 0 0 0 0 0 0 0 0 R32 A a A HFO-1132(E) 100 − R32 − HFO − 1123 100 − R32 − HFO − 1123 100 − R32 − HFO − 1123 approximate expression HFO-1123 0.016a2 − 1.02a + 22.4 0.0161a2 − 0.9959a + 22.149 0.0263a2 − 1.3107a + 24.556 approximate expression R1234yf 0 0 0 approximate expression

Three points corresponding to point B′ were obtained in each of the following three ranges by calculation, and their approximate expressions were obtained.

TABLE 15 Item 10.0 ≥ R32 ≥ 0 16.5 ≥ R32 ≥ 10.0 21.8 ≥ R32 ≥ 16.5 R32 0 5 10 10 14.3 16.5 16.5 19.2 21.8 HFO-1132(E) 56 48.9 41.4 41.4 34.5 31.2 31.2 25.8 20 HFO-1123 26.3 24.1 22.8 22.8 22.8 23 23 25.2 26.9 R1234yf 17.7 22 25.8 25.8 28.4 29.3 29.3 29.8 31.3 R32 a a a HFO-1132(E) −0.008a2 − 1.38a + 56 0.0161a2 − 1.9959a + 59.749 −0.0435a2 − 0.4456a + 50.406 approximate expression HFO-1123 0.018a2 − 0.53a + 26.3 0.014a2 − 0.3399a + 24.8 −0.0304a2 + 1.8991a − 0.0661 approximate expression R1234yf 100 − R32 − HFO − 1132(E) − HFO − 1123 100 − R32 − HFO − 1132(E) − HFO − 1123 100 − R32 − HFO − 1132(E) − HFO − 1123 approximate expression

DESCRIPTION OF REFERENCE NUMERALS

-   1: Sample cell -   2: High-speed camera -   3: Xenon lamp -   4: Collimating lens -   5: Collimating lens -   6: Ring filter 

1. A composition comprising a refrigerant, the refrigerant comprising trans-1,2-difluoroethylene (HFO-1132(E)), trifluoroethylene (HFO-1123), and 2,3,3,3-tetrafluoro-1-propene (R1234yf).
 2. A composition comprising a refrigerant, the refrigerant comprising trans-1,2-difluoroethylene (HFO-1132(E)) and 2,3,3,3-tetrafluoro-1-propene (R1234yf), and optionally further comprising trifluoroethylene (HFO-1123), wherein when the mass % of HFO-1132(E), HFO-1123, and R1234yf based on their sum in the refrigerant is respectively represented by x, y, and z, coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), HFO-1123, and R1234yf is 100 mass % are within the range of a figure surrounded by line segments OD, DG, GH, and HO that connect the following 4 points: point D (87.6, 0.0, 12.4), point G (18.2, 55.1, 26.7), point H (56.7, 43.3, 0.0), and point O (100.0, 0.0, 0.0), or on the line segments OD, DG, and GH (excluding the points O and H); the line segment DG is represented by coordinates (0.0047y²−1.5177y+87.598, y, −0.0047y²+0.5177y+12.402), the line segment GH is represented by coordinates (−0.0134z²−1.0825z+56.692, 0.0134z²+0.0825z+43.308, z), and the line segments HO and OD are straight lines.
 3. The composition according to claim 1, wherein when the mass % of HFO-1132(E), HFO-1123, and R1234yf based on their sum in the refrigerant is respectively represented by x, y, and z, coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), HFO-1123, and R1234yf is 100 mass % are within the range of a figure surrounded by line segments LG, GH, HI, and IL that connect the following 4 points: point L (72.5, 10.2, 17.3), point G (18.2, 55.1, 26.7), point H (56.7, 43.3, 0.0), and point I (72.5, 27.5, 0.0), or on the line segments LG, GH, and IL (excluding the points H and I); the line segment LG is represented by coordinates (0.0047y²−1.5177y+87.598, y, −0.0047y²+0.5177y+12.402), the line segment GH is represented by coordinates (−0.0134z²−1.0825z+56.692, 0.0134z²+0.0825z+43.308, z), and the line segments HI and IL are straight lines.
 4. The composition according to claim 1, further comprising R32.
 5. The composition according to claim 4, wherein when the mass % of HFO-1132(E), HFO-1123, R1234yf, and R32 based on their sum in the refrigerant is respectively represented by x, y, z, and a, if 0<a≤10.0, coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), HFO-1123, and R1234yf is (100-a) mass % are within the range of a figure surrounded by straight lines that connect the following 4 points: point A (0.02a²−2.46a+93.4, 0, −0.02a²+1.46a+6.6), point B′(−0.008a²−1.38a+56, 0.018a²−0.53a+26.3, −0.01a²+0.91a+17.7), point C (−0.016a²+0.02a+77.6, 0.016a²−1.02a+22.4, 0), and point O (100.0-a, 0.0, 0.0), or on the straight lines OA, AB′, and B′C (excluding the points O and C); if 10.0<a≤16.5, coordinates (x,y,z) in the ternary composition diagram are within the range of a figure surrounded by straight lines that connect the following 4 points: point A (0.0244a²−2.5695a+94.056, 0, −0.0244a²+1.5695a+5.944), point B′(0.0161a²-1.9959a+59.749, 0.014a²−0.3399a+24.8, −0.0301a²+1.3358a+15.451), point C (−0.0161a²−0.0041a+77.851, 0.0161a²−0.9959a+22.149, 0), and point O (100.0-a, 0.0, 0.0), or on the straight lines OA, AB′, and B′C (excluding the points O and C); or if 16.5<a≤21.8, coordinates (x,y,z) in the ternary composition diagram are within the range of a figure surrounded by straight lines that connect the following 4 points: point A (0.0161a²−2.3535a+92.742, 0, −0.0161a²+1.3535a+7.258), point B′(−0.0435a²−0.4456a+50.406, −0.0304a²+1.8991a−0.0661, 0.0739a²−2.4535a+49.6601), point C (−0.0263a²+0.3107a+75.444, 0.0263a²−1.3107a+24.556, 0), and point O (100.0-a, 0.0, 0.0), or on the straight lines OA, AB′, and B′C (excluding the points O and C).
 6. The composition according to claim 1, for use as a working fluid for a refrigerating machine, wherein the composition further comprises a refrigeration oil.
 7. The composition according to claim 1, for use as an alternative refrigerant for R410A.
 8. Use of the composition according to claim 1 as an alternative refrigerant for R410A.
 9. A refrigerating machine comprising the composition according to claim 1 as a working fluid.
 10. A method for operating a refrigerating machine, comprising the step of circulating the composition according to claim 1 as a working fluid in a refrigerating machine.
 11. The composition according to claim 2, further comprising R32.
 12. The composition according to claim 11, wherein when the mass % of HFO-1132(E), HFO-1123, R1234yf, and R32 based on their sum in the refrigerant is respectively represented by x, y, z, and a, if 0<a≤10.0, coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), HFO-1123, and R1234yf is (100-a) mass % are within the range of a figure surrounded by straight lines that connect the following 4 points: point A (0.02a²−2.46a+93.4, 0, −0.02a²+1.46a+6.6), point B′(−0.008a²−1.38a+56, 0.018a²−0.53a+26.3, −0.01a²+0.91a+17.7), point C (−0.016a²+0.02a+77.6, 0.016a²−1.02a+22.4, 0), and point O (100.0-a, 0.0, 0.0), or on the straight lines OA, AB′, and B′C (excluding the points O and C); if 10.0<a≤16.5, coordinates (x,y,z) in the ternary composition diagram are within the range of a figure surrounded by straight lines that connect the following 4 points: point A (0.0244a²−2.5695a+94.056, 0, −0.0244a²+1.5695a+5.944), point B′(0.0161a²-1.9959a+59.749, 0.014a²−0.3399a+24.8, −0.0301a²+1.3358a+15.451), point C (−0.0161a²−0.0041a+77.851, 0.0161a²−0.9959a+22.149, 0), and point O (100.0-a, 0.0, 0.0), or on the straight lines OA, AB′, and B′C (excluding the points O and C); or if 16.5<a≤21.8, coordinates (x,y,z) in the ternary composition diagram are within the range of a figure surrounded by straight lines that connect the following 4 points: point A (0.0161a²−2.3535a+92.742, 0, −0.0161a²+1.3535a+7.258), point B′(−0.0435a²−0.4456a+50.406, −0.0304a²+1.8991a−0.0661, 0.0739a²−2.4535a+49.6601), point C (−0.0263a²+0.3107a+75.444, 0.0263a²−1.3107a+24.556, 0), and point O (100.0-a, 0.0, 0.0), or on the straight lines OA, AB′, and B′C (excluding the points O and C).
 13. The composition according to claim 2, for use as a working fluid for a refrigerating machine, wherein the composition further comprises a refrigeration oil.
 14. The composition according to claim 2, for use as an alternative refrigerant for R410A.
 15. Use of the composition according to claim 2 as an alternative refrigerant for R410A.
 16. A refrigerating machine comprising the composition according to claim 2 as a working fluid.
 17. A method for operating a refrigerating machine, comprising the step of circulating the composition according to claim 2 as a working fluid in a refrigerating machine. 